Hybrid memory system and method of operating the same

ABSTRACT

The present disclosure provides a hybrid memory system and a method of operating the same. The hybrid memory system includes a non-volatile memory, a volatile memory and a controller. The volatile memory stores data. The controller is configured to move the data from the volatile memory to the non-volatile memory in response to a command to enter a power-saving mode. The controller precludes the volatile memory from having a self-refresh operation performed thereon after the movement of the data.

PRIORITY CLAIM AND CROSS-REFERENCE

This application claims the benefit of provisional application Ser.62/609,641 filed on Dec. 22, 2017 and entitled “METHOD OF OPERATING ADRAM,” the disclosure of which is hereby incorporated by reference inits entirety.

TECHNICAL FIELD

The present disclosure relates to a hybrid memory system and a method ofoperating the same, and more particularly, to a hybrid memory systemincluding a volatile memory and a non-volatile memory.

DISCUSSION OF THE BACKGROUND

Dynamic random access memory (DRAM) is a type of random access memorythat stores each bit of data in a separate capacitor. A simplest DRAMcell comprises a single N-type metal-oxide-semiconductor (NMOS)transistor and a single capacitor. If charge is stored in the capacitor,the cell is said to store a logic HIGH, depending on the conventionused. If no charge is present, the cell is said to store a logic LOW.Because the charge in the capacitor dissipates over time, DRAM systemsrequire additional refreshing circuitries to periodically refresh thecharge stored in the capacitors. Since a capacitor can store only a verylimited amount of charge, in order to quickly distinguish the differencebetween a logic HIGH and a logic LOW, two bit lines (BLs) are typicallyused for each bit, wherein the first bit line in the bit line pair isknown as a bit line true (BLT) and the other bit line in the bit linepair is the bit line complement (BLC). The single NMOS transistor's gateis controlled by a word line (WL). To maintain data integrity, it isrequired to perform a refresh operation, resulting in power consumption.

This Discussion of the Background section is for background informationonly. The statements in this Discussion of the Background are not anadmission that the subject matter disclosed in this section constitutesa prior art to the present disclosure, and no part of this section maybe used as an admission that any part of this application, includingthis Discussion of the Background section, constitutes prior art to thepresent disclosure.

SUMMARY

One aspect of the present disclosure provides a hybrid memory system.The hybrid memory system includes a non-volatile memory, a volatilememory and a controller. The volatile memory is configured to storedata. The controller is configured to move the data from the volatilememory to the non-volatile memory in response to a command whichrequests to enter a power-saving mode. The controller is configured topreclude the volatile memory from having a self-refresh operationperformed thereon after the movement of the data.

In some embodiments, the controller is further configured to move avalid data from the volatile memory to the non-volatile memory inresponse to the command.

In some embodiments, the controller is further configured to precludethe volatile memory from having the self-refresh operation performedthereon after the movement of the valid data.

In some embodiments, the controller is further configured to identifythe valid data from the data.

In some embodiments, the volatile memory includes a first refresh areaand a second refresh area. The first refresh area is configured to storea first quantity of a first valid data. The second refresh area isconfigured to store a second quantity, less than the first quantity, ofa second valid data. The controller is further configured to move onlythe second valid data to the non-volatile memory in response to thecommand. The controller is further configured to preclude the secondrefresh area from having a partial-self-refresh operation performedthereon after the movement of the second valid data.

In some embodiments, the controller is further configured to allow thefirst refresh area to have the partial-self-refresh operation performedthereon after the movement of the second valid data.

In some embodiments, the volatile memory includes a memory row. Thenon-volatile memory is configured to store a valid data from the memoryrow in response to the command. The controller is further configured tomove the valid data from the non-volatile memory back to the volatilememory in response to a command to exit from the power-saving mode. Thememory row stores no valid data after the movement of the valid datahack to the volatile memory. The controller is further configured topreclude the memory row from having a partial-self-refresh operationperformed thereon after the movement of the valid data back to thevolatile memory.

In some embodiments, the volatile memory includes a first memory row anda second memory row. The non-volatile memory is configured to store afirst valid data from the first memory row and a second valid data fromthe second memory row in response to the command. The controller isfurther configured to move the first valid data and the second validdata from the non-volatile memory back to the first memory row inresponse to a command to exit from the power-saving mode. After themovement of the first valid data and the second valid data back to thefirst memory row, the controller is further configured to allow thefirst memory row to have a partial-self-refresh operation performedthereon and preclude the second memory row from having thepartial-self-refresh operation performed thereon.

In some embodiments, after the movement of the first valid data and thesecond valid data back to the first memory row, the controller isfurther configured to allow the first memory row to be accessed.

Another aspect of the present disclosure provides a hybrid memorysystem. The hybrid memory system comprises a volatile memory and anon-volatile memory. The volatile memory includes a first memory row anda second memory row. The non-volatile memory is configured to store afirst valid data from the first memory row and a second valid data fromthe second memory row in response to a command to enter a power-savingmode. The controller is configured to, in response to a command to exitfrom the power-saving mode, move both the first valid data and thesecond valid data to the first memory row. The controller is configuredto preclude the second memory row, in response to the command, frombeing accessed for the second valid data.

In some embodiments, the controller is further configured to precludethe second memory row from having the partial-self-refresh operationperformed thereon.

Another aspect of the present disclosure provides a method. The methodcomprises: storing data in a volatile memory; moving the data from thevolatile memory to a non-volatile memory in response to a command toenter a power-saving mode; and precluding the volatile memory fromhaving a self-refresh operation performed thereon after the movement ofthe data.

In some embodiments, the method further comprises: storing a valid datain the volatile memory; moving the valid data from the volatile memoryto the non-volatile memory in response to the command; and precludingthe volatile memory from having a self-refresh operation performedthereon after the movement of the valid data.

In some embodiments, the method further comprises: precluding thevolatile memory from having the self-refresh operation performed thereonafter the movement of the valid data.

In some embodiments, the method further comprises: (1) storing a firstquantity of a first valid data by a first refresh area; (2) storing asecond quantity, less than the first quantity, of a second valid data bya second refresh area; (3) moving only the second valid data to thenon-volatile memory in response to the command; and (4) precluding thesecond refresh area from having a partial-self-refresh operationperformed thereon after the movement of the second valid data.

In some embodiments, the method further comprises: allowing the firstrefresh area to have the partial-self-refresh operation performedthereon after the movement of the second valid data.

In some embodiments, the method further comprises: storing a valid datafrom a memory row of the volatile memory in the non-volatile memory inresponse to the command; moving the valid data from the non-volatilememory back to the volatile memory in response to a command to exit fromthe power-saving mode; and precluding the memory row from having thepartial-self-refresh operation performed thereon after the movement ofthe valid data back to the volatile memory, wherein the memory rowstores no valid data after the movement of the valid data back to thevolatile memory.

In some embodiments, the method further comprises: precluding the memoryrow from being accessed for the valid data after the movement of thevalid data back to the volatile memory.

In some embodiments, the method further comprises: storing a first validdata from a first memory row of the volatile memory in the non-volatilememory in response to the command; storing a second valid data from asecond memory row of the volatile memory in the non-volatile memory inresponse to the command; moving the first valid data and the secondvalid data from the non-volatile memory back to the first memory row inresponse to a command to exit from the power-saving mode; and allowingthe first memory row to have a partial-self-refresh operation performedthereon and precluding the second memory row from having thepartial-self-refresh operation performed thereon after the movement ofthe first valid data and the second valid data back to the first memoryrow.

In the present disclosure, since the volatile memory 14 in thepower-saving mode is disabled while data integrity is still maintained,power consumption of the volatile memory in the power-saving mode isrelatively efficient.

In some existing DRAMs, it is still necessary to perform a self-refreshoperation on the DRAMs in a power-saving mode in order to maintain dataintegrity. Hence, power consumption of the DRAMs is relativelyinefficient.

The foregoing has outlined rather broadly the features and technicaladvantages of the present disclosure in order that the detaileddescription of the disclosure that follows may be better understood.Additional features and technical advantages of the disclosure aredescribed hereinafter, and form the subject of the claims of thedisclosure. It should be appreciated by those skilled in the art thatthe concepts and specific embodiments disclosed may be utilized as abasis for modifying or designing other structures, or processes, forcarrying out the purposes of the present disclosure. It should also berealized by those skilled in the art that such equivalent constructionsdo not depart from the spirit or scope of the disclosure as set forth inthe appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present disclosure may be derivedby referring to the detailed description and claims. The disclosureshould also be understood to be connected to the figures' referencenumbers, which refer to similar elements throughout the description.

FIG. 1 is a schematic diagram of a hybrid memory system, in accordancewith some embodiments of the present disclosure.

FIG. 2 is a flow chart of a method of operating a hybrid memory system,in accordance with some embodiments of the present disclosure.

FIG. 3 is a schematic diagram of the hybrid memory system shown in FIG.1 in a scenario, in accordance with some embodiments of the presentdisclosure.

FIG. 4 is a schematic diagram illustrating a movement operation from thevolatile memory to the non-volatile memory in the scenario of FIG. 3, inaccordance with some embodiments of the present disclosure.

FIG. 5 is a schematic diagram illustrating a disabling operation in thescenario of FIG. 3, in accordance with some embodiments of the presentdisclosure.

FIG. 6 is a flow chart of another method of operating a hybrid memorysystem, in accordance with some embodiments of the present disclosure.

FIG. 7 is a schematic diagram of the hybrid memory system shown in FIG.1 in another scenario, in accordance with some embodiments of thepresent disclosure.

FIG. 8 is a schematic diagram illustrating a movement operation from thevolatile memory to the non-volatile memory in the scenario of FIG. 7, inaccordance with some embodiments of the present disclosure.

FIG. 9 is a schematic diagram illustrating a disabling operation in thescenario of FIG. 7, in accordance with some embodiments of the presentdisclosure.

FIG. 10 is a schematic diagram illustrating a partial-self-refreshoperation in the scenario of FIG. 7, in accordance with some embodimentsof the present disclosure.

FIG. 11 is a flow chart of yet another method of operating a hybridmemory system, in accordance with some embodiments of the presentdisclosure.

FIG. 12 is a schematic diagram illustrating another movement operationfrom the non-volatile memory to the volatile memory, in accordance withsome embodiments of the present disclosure.

FIG. 13 is a schematic diagram illustrating another refresh operation,in accordance with some embodiments of the present disclosure.

FIG. 14 is a schematic diagram illustrating an access operation of thehybrid memory system shown in FIG. 1, in accordance with someembodiments of the present disclosure.

FIG. 15 is a flow chart of still another method of operating a hybridmemory system, in accordance with some embodiments of the presentdisclosure.

DETAILED DESCRIPTION

Embodiments, or examples, of the disclosure illustrated in the drawingsare now described using specific language. It shall be understood thatno limitation of the scope of the disclosure is hereby intended. Anyalteration or modification of the described embodiments, and any furtherapplications of principles described in this document, are to beconsidered as normally occurring to one of ordinary skill in the art towhich the disclosure relates. Reference numerals may be repeatedthroughout the embodiments, but this does not necessarily mean thatfeature(s) of one embodiment apply to another embodiment, even if theyshare the same reference numeral.

It shall be understood that, although the terms first, second, third,etc. may be used herein to describe various elements, components,regions, layers or sections, these elements, components, regions, layersor sections are not limited by these terms. Rather, these terms aremerely used to distinguish one element, component, region, layer orsection from another region, layer or section. Thus, a first element,component, region, layer or section discussed below could be termed asecond element, component, region, layer or section without departingfrom the teachings of the present inventive concept.

The terminology used herein is for the purpose of describing particularexample embodiments only and is not intended to be limited to thepresent inventive concept. As used herein, the singular forms “a,” “an”and “the” are intended to include the plural forms as well, unless thecontext clearly indicates otherwise. It shall be further understood thatthe terms “comprises” and “comprising,” when used in this specification,point out the presence of stated features, integers, steps, operations,elements, or components, but do not preclude the presence or addition ofone or more other features, integers, steps, operations, elements,components, or groups thereof.

FIG. 1 is a schematic diagram of a hybrid memory system 10, inaccordance with some embodiments of the present disclosure. Referring toFIG. 1, the hybrid memory system 10 includes a non-volatile memory 12, avolatile memory 14, a refresh device 16, an access device 17 and acontroller 18. In the present embodiment, the hybrid memory system 10 isintegrated in a device, and enclosed in a housing. However, the presentdisclosure is not limited thereto.

The non-volatile memory 12 functions to store data. In an embodiment,the non-volatile memory 12 includes a NAND flash memory. In otherembodiments, the non-volatile memory 12 includes a read-only memory(ROM), a programmable read-only memory (PROM), an electrically alterableread-only memory (EAROM), an erasable programmable read-only memory(EPROM), or an electrically erasable programmable read-only memory(EEPROM).

The volatile memory 14 functions to store data. The volatile memory 14,in the present embodiment, includes a dynamic random access memory(DRAM). The volatile memory 14 includes a memory array. The memory arrayincludes a plurality of memory cells 140. The memory cell 140 functionsto store data. In addition to the memory cells 140, the memory arrayfurther includes a plurality of word lines WL1 to WLn and a plurality ofbit lines BL1 to BLm, wherein n and m are positive integers. The wordlines WL1 to WLn and the bit lines BL1 to BLm are used to controloperation of the associated memory cells 140. The memory cells 140 in asingle row and a word line for accessing those memory cells 140 cantogether be deemed as a memory row. However, the present disclosure isnot limited thereto.

The refresh device 16 functions to perform a self-refresh operation onthe volatile memory 14. The self-refresh operation refers to theprocedure in which the refresh device 16 automatically executes arefresh operation by, for example, using an internal refresh counter.There is no need for the refresh device 16 to obtain refresh requestfrom, for example, a processor external to the hybrid memory system 10to perform the self-refresh operation. The refresh device 16 and/orother devices in the hybrid memory system 10 can generate, on their own,any information required to perform the self-refresh operation.Additionally, the refresh device 16 refreshes the volatile memory 14 ina fashion in which, for example, a charge is read from the memory cell140, and the charge is immediately written hack to the memory cell 140.However, the present disclosure is not limited thereto. The refreshoperation may further include other detailed operations.

The access device 17, connected to the refresh device 16 and thevolatile memory 14, functions to access the volatile memory 14 to obtainthe data stored in the volatile memory 14, in particular, the memorycell 140.

The controller 18, connected to the refresh device 16 and thenon-volatile memory 12, functions to control the refresh device 16 andthe access device 17. In particular, the controller 18 functions tocontrol a movement of a data between the non-volatile memory 12 and thevolatile memory 14.

During operation, the controller 18 receives a command to enter apower-saving mode, and, in response to the command, moves data stored inthe volatile memory 14 from the volatile memory 14 to the nonvolatilememory 12.

Generally, in a power-saving mode, a refresh device is required toperform a self-refresh operation on a volatile memory to maintain dataintegrity.

Since the data was moved from the volatile memory 14 to the non-volatilememory 12, there is no data stored in the volatile memory 14. Thus,there is no longer a need for the self-refresh operation to be performedon the volatile memory 14 to maintain data integrity. Accordingly, bydisabling the self-refresh function on the volatile memory 14, thecontroller 18 precludes the volatile memory 14 from having theself-refresh operation performed thereon after the movement of the dataand in particular in the power-saving mode.

In the present disclosure, since the volatile memory 14 in thepower-saving mode is disabled, power consumption of the volatile memory14 in the power-saving mode is relatively efficient.

In some existing DRAMs, it is still necessary to perform a self-refreshoperation on the DRAMs in a power-saving mode to maintain dataintegrity. Hence, power consumption the DRAMs is relatively inefficient.

FIG. 2 is a flow chart of a method 20 of operating a hybrid memorysystem, in accordance with some embodiments of the present disclosure.Referring to FIG. 2, the method 20 includes operations 22 and 24.

The method 20 begins with operation 22, in which data stored in avolatile memory is moved from the volatile memory to a non-volatilememory in response to a command to enter a power-saving mode.

The method 20 proceeds to operation 24, in which the volatile memory isprecluded from having a self-refresh operation performed thereon afterthe movement of the data and in particular in the power-saving mode.

The method 20 is merely an example, and is not intended to limit thepresent disclosure beyond what is explicitly recited in the claims.Additional operations can be provided before, during, and after themethod 20, and some operations described can be replaced, eliminated, ormoved around for additional embodiments of the method.

In the present disclosure, power consumption of a hybrid memory systemadopting the method 20 is relatively efficient in a power-saving mode.

FIG. 3 is a schematic diagram of the hybrid memory system 10 shown inFIG. 1 in a scenario, in accordance with some embodiments of the presentdisclosure. Referring to FIG. 3, in the scenario, the volatile memory 14stores a data including a valid data 140 and an invalid data 142. In thepresent embodiment, the valid data 140 refers to data which will be usedby the controller 18 or an external processor (not shown) electricallyconnected to the hybrid memory system 10. Conversely, the invalid data142 refers to data which will not be used. However, the presentdisclosure is not limited thereto. In other embodiments, there may beanother appropriate basis on which to classify a valid data and aninvalid data.

During operation, the controller 18 identifies the valid data 140 fromthe data according to the information provided by the externalprocessor.

FIG. 4 is a schematic diagram illustrating a movement operation from thevolatile memory 14 to the non-volatile memory 12 in the scenario of FIG.3, in accordance with some embodiments of the present disclosure.Referring to FIG. 4, subsequent to the identification, the controller 18moves the valid data 140 from the volatile memory 14 to the non-volatilememory 12 in response to the command.

Since only the valid data 140 is moved (i.e., the invalid data 142 isnot moved), power consumption of the volatile memory 14 is relativelyefficient.

FIG. 5 is a schematic diagram illustrating a disabling operation in thescenario of FIG. 3, in accordance with some embodiments of the presentdisclosure. Referring to FIG. 5, by disabling the volatile memory 14,the controller 18 precludes the volatile memory 14 from having theself-refresh operation performed thereon after the movement of the validdata 140 and in particular in the power-saving is mode.

Without the self-refresh operation in the power-saving mode, the invaliddata 142 will eventually be lost. However, the invalid data 142 will notbe used. Hence, data integrity is not affected.

In the present disclosure, since the volatile memory 14 in thepower-saving mode is disabled, power consumption of the volatile memory14 in the power-saving mode is relatively efficient.

FIG. 6 is a flow chart of another method 30 of operating a hybrid memorysystem, in accordance with some embodiments of the present disclosure.Referring to FIG. 6, the method 30 includes operations 32, 34 and 36.

The method 30 begins with operation 32, in which a valid data isidentified from data stored in a volatile memory.

The method 30 proceeds to operation 34, in which the valid data is movedfrom the volatile memory to a non-volatile memory in response to acommand to enter a power-saving mode.

The method 30 continues with operation 36, in which the volatile memorywithout the valid data is precluded from having a self-refresh operationperformed thereon after the movement of the valid data and in particularin the power-saving mode.

The method 30 is merely an example, and is not intended to limit thepresent disclosure beyond what is explicitly recited in the claims.Additional operations can be provided before, during, and after themethod 30, and some operations described can be replaced, eliminated, ormoved around for additional embodiments of the method.

In the present disclosure, power consumption of a hybrid memory systemadopting the method 30 is relatively efficient in a power-saving mode.

FIG. 7 is a schematic diagram of the hybrid memory system 10 shown inFIG. 1 in another scenario, in accordance with some embodiments of thepresent disclosure. Referring to FIG. 7, the volatile memory 14 includesa first refresh area 40 and a second refresh area 42.

The first refresh area 40 stores first valid data 400, 402 and 404. Suchquantity of the valid data only serves as an example. The first refresharea 40, in some embodiments, includes a plurality of memory rows.However, the present disclosure is not limited thereto. In someembodiments, the first refresh area 40 includes a single memory row.Moreover, in some embodiments, the memory rows of the first refresh area40 belong to a single bank. However, the present disclosure is notlimited thereto. The memory rows may belong to different banks. That is,the first refresh area 40 may include a single bank, a plurality ofbanks, a single memory row, or a plurality of memory rows. The presentdisclosure is not limited to any specific type as previously mentioned.

The second refresh area 42 stores second valid data 420 and 422. Thatis, a second quantity of the second valid data is less than the firstquantity of the first valid data. Such quantity of valid data onlyserves as an example. The second refresh area 42 includes a plurality ofmemory rows. However, the present disclosure is not limited thereto. Insome embodiments, the second refresh area 42 includes a single memoryrow. Moreover, in some embodiments, the memory rows of the secondrefresh area 42 belong to a single bank. However, the present disclosureis not limited thereto. The memory rows may belong to different banks.That is, the second refresh area 42 may include a single bank, aplurality of banks, a single memory row, or a plurality of memory rows.The present disclosure is not limited to any specific type as previouslymentioned.

During operation, the controller 18 determines that the second quantityis less than the first quantity according to a storing data record whichis maintained by the information from the external processor.

FIG. 8 is a schematic diagram illustrating a movement operation from thevolatile memory 14 to the non-volatile memory 12 in the scenario of FIG.7, in accordance with some embodiments of the present disclosure.Referring to FIG. 8, the controller 18 moves only the second valid data420 and 422 (i.e., moves the lesser second quantity) to the non-volatilememory 12 in response to the command.

FIG. 9 is a schematic diagram illustrating a disabling operation in thescenario of FIG. 7, in accordance with some embodiments of the presentdisclosure. Referring to FIG. 9, the controller 18 disables the secondrefresh area 42 whose valid data 420 and 422 was moved to thenon-volatile memory 12.

FIG. 10 is a schematic diagram illustrating a partial-self-refreshoperation in the scenario of FIG. 7, in accordance with some embodimentsof the present disclosure. Referring to FIG. 10, by disabling the secondrefresh area 42, the controller 18 precludes the second refresh area 42from having a partial-self-refresh operation performed thereon after themovement of the second valid data 420 and 422. However, the controller14 allows the first refresh area 40 to have the partial-self-refreshoperation performed thereon to maintain data integrity of the firstvalid data 400, 402 and 404.

In the present disclosure, in a power-saving mode, instead of aself-refresh operation, a partial-self-refresh operation is performed.As a result, power consumption of the volatile memory 14 in thepower-saving mode is relatively efficient.

In some existing DRAMs, in a power-saving mode, a self-refresh operationis performed, such that all of refresh areas of the DRAMs are requiredto be refreshed. As a result, power consumption of the DRAMs isrelatively inefficient.

FIG. 11 is a flow chart of yet another method 50 of operating a hybridmemory system, in accordance with some embodiments of the presentdisclosure. Referring to FIG. 11, the method 50 includes operations 52,54, 56 and 58.

The method 50 begins with operation 52, in which a valid data isidentified from data stored in each of a first refresh area and a secondrefresh area.

The method 50 proceeds to operation 54, in which it is determined thatthe first refresh area stores a greater quantity of valid data than thesecond refresh area.

The method 50 continues with operation 56, in which the valid data ismoved from the second refresh area to a non-volatile memory in responseto a command to enter a power-saving mode.

The method 50 continues with operation 58, in which the second refresharea is precluded from having a partial-self-refresh operation performedthereon after the movement of the valid data.

The method 50 is merely an example, and is not intended to limit thepresent disclosure beyond what is explicitly recited in the claims.Additional operations can be provided before, during, and after themethod 50, and some operations described can be replaced, eliminated, ormoved around for additional embodiments of the method.

In the present disclosure, power consumption of a hybrid memory systemadopting the method 50 is relatively efficient in a power-saving mode.

FIG. 12 is a schematic diagram illustrating another movement operationfrom the non-volatile memory 12 to the volatile memory 14, in accordancewith some embodiments of the present disclosure. Operations describedand illustrated with reference to FIGS. 12 to 14 are able to besubsequent to each of a first embodiment shown in FIG. 1, a secondembodiment shown in FIGS. 3 to 5, and a third embodiment shown in FIGS.7 to 10, when appropriate.

Referring to FIG. 12, the volatile memory 14 includes a first memory row60, a second memory row 62 and a third memory row 64.

The first memory row 60 includes memory spaces 600, 602 and 604.

The second memory row 62 includes memory spaces 620, 622 and 624.

The third memory row 64 includes memory spaces 640, 642 and 644.

The non-volatile memory 12 stores first valid data 630 and 632 from thefirst memory row 60, second valid data 634 and 636 from the secondmemory row 62 and third valid data 638 from the third memory row 64 inresponse to the command.

During operation, the controller 18, in response to a command to exitfrom the power-saving mode, moves the valid data 630, 632, 634, 636 and638 back to the first memory row 60 until the first memory row 60 has nosufficient memory spaces to store more valid data. Next, the controller18 moves the remaining valid data to the second memory row 62.

FIG. 13 is a schematic diagram illustrating another refresh operation,in accordance with some embodiments of the present disclosure. Referringto FIG. 13, in further detail, the controller 18 moves the first validdata 630 and 632 and the second valid data 634 from the non-volatilememory 12 back to the memory spaces 600, 602, and 604, respectively, ofthe first memory row 60, in response to a command to exit from thepower-saving mode.

Moreover, the controller 18 moves the second valid data 636 and thethird valid data 638 from the non-volatile memory 12 back to the memoryspaces 620 and 622, respectively, of the second memory row 62, inresponse to a command to exit from the power-saving mode.

The third memory row 64, which provided the third valid data 638 inresponse to a command to enter a power-saving mode, does not store anyvalid data from the non-volatile memory 12 in response to a command toexit from the power-saving mode. In short, the valid data 630, 632, 634,636 and 638 are centralized to the first memory row 60 and the secondmemory row 62.

After the movement of the valid data 630, 632, 634, 636 and 638 back tothe volatile memory 14, the controller 16 allows the first memory row 60and the second memory row 62 to have a partial-self-refresh operationperformed thereon to maintain data integrity of the valid data 630, 632,634, 636 and 638. Moreover, the controller 16 precludes the third memoryrow 64 from having the partial-self-refresh operation performed thereon.As a result, as discussed in the embodiment of FIG. 10, powerconsumption of the volatile memory 14 in the power-saving mode isrelatively efficient.

FIG. 14 is a schematic diagram illustrating an access operation of thehybrid memory system 10 shown in FIG. 1, in accordance with someembodiments of the present disclosure. Referring to FIG. 14, after themovement of the valid data 630, 632, 634, 636 and 638 back to thevolatile memory 14, the controller 18 allows the first memory row 60 andthe second memory row 62 to be accessed and prohibits the third memoryrow 64 from being accessed for the valid data 638.

Generally, to access a data from a memory row, it is necessary toperform many preparation operations, such as a pre-charge operation, anactive operation, and/or other operations.

In the present embodiment, the third valid data 638, which was providedby the third memory row 64, is stored with the second valid data 636 inthe second memory row 62. There is no need to perform the preparationoperation to access the third memory row 64 when it is necessary toaccess the third valid data 638. In further detail, the preparationoperation, which would otherwise be performed for three memory rows 60,62 and 64, are performed for only two memory rows 60 and 62. As aresult, an access of the volatile memory 14 is relatively efficient.

FIG. 15 is a flow chart of still another method 70 of operating a hybridmemory system, in accordance with some embodiments of the presentdisclosure. Referring to FIG. 15, the method 70 includes operations 700,702, 704, 706, 708, 710 and 712.

The method 70 begins with operation 700, in which a first valid datafrom a first memory row is stored in a non-volatile memory in responseto a command to enter a power-saving mode.

The method 70 proceeds to operation 702, in which a second valid datafrom a second memory row is stored in the non-volatile memory inresponse to the command.

The method 70 continues with operation 704, in which the first validdata and the second valid data are moved from the non-volatile memoryback to the first memory row in response to a command to exit from thepower-saving mode.

The method 70 proceeds to operation 706, in which the first memory rowis allowed to have a partial-self-refresh operation performed thereonafter the movement of the first valid data and the second valid databack to the first memory row.

The method 70 continues with operation 708, in which the second memoryrow is precluded from having the partial-self-refresh operationperformed thereon after the movement of the valid data.

The method 70 proceeds to operation 710, in which the first memory rowis allowed to be accessed.

The method 70 continues with operation 712, in which the second memoryrow is prohibited from being accessed for the second valid data.

The method 70 is merely an example, and is not intended to limit thepresent disclosure beyond what is explicitly recited in the claims.Additional operations can be provided before, during, and after themethod 70, and some operations described can be replaced, eliminated, ormoved around for additional embodiments of the method.

In the present disclosure, power consumption of a hybrid memory systemadopting the method 70 is relatively efficient in a power-saving mode.

In the present disclosure, since the volatile memory 14 in thepower-saving mode is disabled, power consumption of the volatile memory14 in the power-saving mode is relatively efficient.

One aspect of the present disclosure provides a hybrid memory system.The hybrid memory system includes a non-volatile memory, a volatilememory and a controller. The volatile memory is configured to storedata. The controller is configured to move the data from the volatilememory to the non-volatile memory in response to a command to enter apower-saving mode. The controller is configured to preclude the volatilememory from having a self-refresh operation performed thereon after themovement of the data.

Another aspect of the present disclosure provides a hybrid memorysystem. The hybrid memory system comprises a volatile memory and anon-volatile memory. The volatile memory includes a first memory row anda second memory row. The non-volatile memory is configured to store afirst valid data from the first memory row and a second valid data fromthe second memory row, in response to a command to enter a power-savingmode. The controller is configured to, in response to a command to exitfrom the power-saving mode, move both the first valid data and thesecond valid data to the first memory row. The controller is configuredto, in response to the command, preclude the second memory row frombeing accessed for the second valid data.

Another aspect of the present disclosure provides a method. The methodcomprises storing data in a volatile memory; moving the data from thevolatile memory to a non-volatile memory in response to a command toenter a power-saving mode; and precluding the volatile memory fromhaving a self-refresh operation performed thereon after the movement ofthe data.

Although the present disclosure and its advantages have been describedin detail, it should be understood that various changes, substitutionsand alterations can be made herein without departing from the spirit andscope of the disclosure as defined by the appended claims. For example,many of the processes discussed above can be implemented in differentmethodologies and replaced by other processes, or a combination thereof.

Moreover, the scope of the present application is not intended to belimited to the particular embodiments of the process, machine,manufacture, and composition of matter, means, methods and stepsdescribed in the specification. As one of ordinary skill in the art willreadily appreciate from the present disclosure, processes, machines,manufacture, compositions of matter, means, methods, or steps, presentlyexisting or later to be developed, that perform substantially the samefunction or achieve substantially the same result as the correspondingembodiments described herein may be utilized according to the presentdisclosure. Accordingly, the appended claims are intended to includewithin their scope such processes, machines, manufacture, compositionsof matter, means, methods, or steps.

What is claimed is:
 1. A hybrid memory system, comprising: anon-volatile memory; a volatile memory configured to store data; and acontroller configured to move at least a portion of the data from thevolatile memory to the non-volatile memory in response to a command toenter a power-saving mode, and to preclude a location of the volatilememory from having a self-refresh operation, wherein the location is alocation from where the portion of the data was moved, wherein thevolatile memory includes: a first refresh area configured to store afirst quantity of a first valid data; and a second refresh areaconfigured to store a second quantity, less than the first quantity, ofa second valid data, wherein the portion of the data is the second validdata, and the first valid data is other portions of the data, whereinthe controller is configured to move only the second valid data to thenon-volatile memory in response to the command, and to preclude thesecond refresh area from having a partial-self-refresh operationperformed thereon after the movement of the second valid data, whereinthe location is the second refresh area, and wherein the controller isconfigured to allow the first refresh area to have thepartial-self-refresh operation performed thereon after the movement ofthe second valid data.
 2. The hybrid memory system of claim 1, whereinthe controller is further configured to identify the first valid dataand the second valid data from the data.
 3. The hybrid memory system ofclaim 1, wherein the volatile memory includes a memory row, wherein thecontroller is further configured to move the first valid data and thesecond valid data from the non-volatile memory back to the volatilememory in response to a command to exit from the power-saving mode,wherein the memory row stores no valid data after the movement of thefirst valid data and the second valid data back to the volatile memory,and wherein the controller is configured to preclude the memory row fromhaving the partial-self-refresh operation performed thereon after themovement of the first valid data and the second valid data back to thevolatile memory.
 4. The hybrid memory system of claim 1, wherein thevolatile memory includes a first memory row and a second memory row,wherein the non-volatile memory is configured to store the first validdata from the first memory row and the second valid data from the secondmemory row in response to the command, wherein the controller is furtherconfigured to move the first valid data and the second valid data fromthe non-volatile memory back to the first memory row in response to acommand to exit from the power-saving mode, and wherein after themovement of the first valid data and the second valid data back to thefirst memory row, the controller is configured to allow the first memoryrow to have a partial-self-refresh operation performed thereon and tocontinue to preclude the second memory row from having thepartial-self-refresh operation performed thereon.
 5. The hybrid memorysystem of claim 4, wherein after the movement of the first valid dataand the second valid data back to the first memory row, the controlleris further configured to allow the first memory row to be accessed.
 6. Ahybrid memory system, comprising: a volatile memory including: a firstmemory row; and a second memory row; a non-volatile memory configured tostore a first valid data from the first memory row and a second validdata from the second memory row, in response to a command to enter apower-saving mode; and a controller configured to, in response to acommand to exit from the power-saving mode, move both the first validdata and the second valid data to the first memory row, and preclude thesecond memory row from being accessed for the second valid data.
 7. Thehybrid memory system of claim 6, wherein the controller is furtherconfigured to preclude the second memory row from having thepartial-self-refresh operation performed thereon.
 8. A method,comprising: storing data in a volatile memory, the data comprising afirst portion and a second portion; storing a first quantity of a firstvalid data by a first refresh area, wherein the first valid data is thefirst portion of the data; storing a second quantity, less than thefirst quantity, of a second valid data by a second refresh area, whereinthe second portion of the data is the second valid data; moving only thesecond valid data from the volatile memory to a non-volatile memory inresponse to a command to enter a power-saving mode; precluding thesecond refresh area from having a partial-self-refresh operationperformed thereon after the movement of the second valid data, and thesecond refresh area is a location from where the second valid data wasmoved; and allowing the first refresh area to have thepartial-self-refresh operation performed thereon after the movement ofthe second valid data.
 9. The method of claim 8, wherein the first validdata and the second valid data are stored from a memory row of thevolatile memory in the non-volatile memory in response to the command;and the method further comprising: moving the first valid data and thesecond valid data from the non-volatile memory back to the volatilememory in response to a command to exit from the power-saving mode; andprecluding the memory row from having the partial-self-refresh operationperformed thereon after the movement of the first valid data and thesecond valid data back to the volatile memory, wherein the memory rowstores no valid data after the movement of the first valid data and thesecond valid data back to the volatile memory.
 10. The method of claim9, further comprising: precluding the memory row from being accessed forthe first valid data and the second valid data after the movement of thefirst valid data and the second valid data back to the volatile memory.11. The method of claim 8, wherein the first valid data is stored from afirst memory row of the volatile memory in the non-volatile memory inresponse to the command; wherein the second valid data is stored from asecond memory row of the volatile memory in the non-volatile memory inresponse to the command; and the method further comprising: moving thefirst valid data and the second valid data from the non-volatile memoryback to the first memory row in response to a command to exit from thepower-saving mode; and allowing the first memory row to have apartial-self-refresh operation performed thereon and continuing topreclude the second memory row from having the partial-self-refreshoperation performed thereon after the movement of the first valid dataand the second valid data back to the first memory row.